A team of machete-wielding rescuers, whose progress was slowed by rain, fog, dense woods and soggy underbrush, had to turn back after a five-hour hike because a steep mountain blocked their passage. Search teams said they found bits of scattered wreckage - but no survivors.
"We saw pieces of wing and other plane parts," said Jose Escobar of the Rio Grande civil defense force. He said rescuers called out for survivors in the wet forest - but no answers came.
A police spokeswoman, Marylin Calo, identified the pilot as Ken Webster, whose nationality was not immediately known. Police did not have confirmed information about the two U.S. tourists aboard the aircraft.
The plane took off from Tortola in the British Virgin Islands and was heading to San Juan, said Jose Daniel Echevarria, a spokesman for Puerto Rico's Department of Emergency Management.
The Rockwell International 690B was about 13 miles east of San Juan, over the El Yunque National Forest, when authorities lost track of it, said Kathleen Bergen, a regional spokeswoman for the Federal Aviation Administration.
Below the mountain, ambulances and other vehicles lined a muddy road where scores of people waited for word on those aboard the aircraft. As evening fell, a second team of emergency workers began struggling through the steady rain and densely forested terrain to reach the remote crash site from a different angle.
"It's not easy," said Filomeno Correa, a coordinator with Puerto Rico's disaster management office, as rescuers crowded around a map trying to figure out the best way to the area. "You take two steps forward and twenty steps back."
Jose Saldana, a restaurant owner near the foothills of the Puerto Rican mountains, said he heard two explosions around noon Wednesday after a low-flying plane passed overhead.
"First it was an impact like when somebody slams the door of a car, and then I heard another boom," Saldana said.
